1. Field of the Invention
The present disclosure relates to a method of manufacturing a solid-state image pickup apparatus such as a CCD sensor and a CMOS sensor.
2. Description of the Related Art
FIG. 1 illustrates a solid-state image pickup apparatus described in Japanese Patent Laid-Open No. 2007-287872. The solid-state image pickup apparatus of FIG. 1 includes photodiodes 33 in a substrate 21, charge transfer electrodes 23 on the substrate 21, the charge transfer electrodes 23 transferring signal charges detected by the photodiodes 33, and microlenses (not shown) that are formed on a surface on a light receiving side. A light shielding film 27 that functions also as a light reflection members is formed above the photodiodes 33 so as to form openings. Furthermore, Japanese Patent Laid-Open No. 2007-287872 discloses, as a method of forming the light shielding film 27, a method in which the light shielding film 27 is formed on a surface of a buffer oxide film and the like after depositing the buffer oxide film and the like on a surface of the charge transfer electrodes 23.
In a solid-state image pickup apparatus, in order to prevent reduction of sensitivity, it is effective to dispose the light reflection members that help collect light to the photodiodes near the photodiodes. Incidentally, in the method of manufacturing the light reflection members described in Japanese Patent Laid-Open No. 2007-287872, the light shielding film 27 is formed on the surface of the buffer oxide film and the like after depositing the buffer oxide film and the like on the surfaces of the charge transfer electrodes 23. However, in the manufacturing method described in Japanese Patent Laid-Open No. 2007-287872, since the light reflection members are formed on a plurality of films after the plurality of films are formed on the charge transfer electrodes, the shapes and positions of the light reflection members are affected by the shapes and positions of the charge transfer electrodes. In other words, in the manufacturing method described in Japanese Patent Laid-Open No. 2007-287872, degree of freedom in setting the shapes and positions of the light reflection members is small. Accordingly, if the matching between the position of the optical system such as the microlenses and the like and the shapes and positions of the light reflection members are insufficient, there are cases in which the light reflected by the light reflection members does not reach the photodiodes. As a result, the light collection efficiency of the photodiodes may not be improved sufficiently.